Ellipsograph.



G. TOTH.

ELLrPsoGRAPH.

APPLICATION FILED DEC. 7| 195. l,188,1 17'. Patented June 20, 1916.

/Q Amm/v y GEYzA TTH, or NEW YORK, N. Y.

ELLIPSOGRAPH.

Specification of Letters Patent. i

Patented June 20, 1916.

Application inea December 7, 1915. serial No. 65,513.

To all whom t may concern:

Be it known that I, GEYZA TTH, a subject of the King of Hungary, and a res1- dent of the city of New York, in the county of NewYork and State of New York, have invented certain new and useful Improvements in Ellipsographs, of which the following is a specification. f

The present invention relates to a scriber designedfor producing curved lines, more particularly ellipses.

One of the objects of the invention is to provide an ellipsograph that is simple rin construction, e'cient in operation, v and which can be manufactured on a commercial scale, or in other words which is not so difcult to produce as to be beyond the reason-y able cost of such a contrivance.

Another object of the invention is. to devise an ellipsograph of this type, upon which can be mounted pencil, 111k-, and

other markingl members. I

A still further object of the invention is to provide adevice of the type mentioned whichis extremely simple to use, and adjustable for describing ellipses of different sizes and forms'.

With these and other objects in view, `which will more fully appear as the nature yof the invention is better understood, the

same consists in the combination, arrangement and construction of parts Ihereinafter fully described, pointed out in thev appended claims and illustratedl in the accompanying drawings, it being understood that many changes maybe made in the size andl proportion of the several parts and details of construction within the scope of the appended claims withoutl departing from `the spirit or sacrificing any of the advantages of the invention.

One ,ofthe many possible embodiments of the invention is illustrated in the ac` 'companying drawings, 1n wh1ch:.

Figure 1 1s a vertical longitudinal section 'taken through an ellipsograph constructed in accordance with the present invention; Fig. 2 is a top plan view thereof; Fig. 3 is a top plan viewof a detail of construction; Fig. 4 is av section taken on line 4 4 of Fig. l; and Fig. 5 is a diagram villustrating the mode ofoperation. of the apparatus. i

In the drawings, the numeral 10 indicates a standard, provided at its lower end with a centering point 11, and at its upper end with a knob 12, the face 13 of i against a ydisk-shaped stop 17, that is fastened, for instance, by means of a pin 18 to the standard 10. The gear 14 is securedto said standard, for instance by a pin 19, the latter passing through the sleeve 15 andthe said standard. Upon the sleeve 15 1s slidably and rotatably mounted a horizontally disposed bar 20, that is provided with adownwardly projecting slotted extension `2l, the said extension resting upon the washer 16, and its top edge abutting against the hub 22 of the gear 14. The sleeve 15 of said gear is seated in the slot of the extension 21, the width of the'slot being substantially of the size of the outer diameter of the said sleeve. With the gear 14 meshes a pinion 23, the ratio between the circumferences of the gear and pinion being, for .a purpose hereinafter to be eX- plained, 2:1. This pinion is disposed above the bar-20, and is connected there- 4,with by means of a lug 24, the latter being made in the form of a screw, that extends through the said bar and projects throught a somewhat curved, vsubstantially radially extending slot 25 in the pinion 23. The upper end of this screw is seated in anaperture 26, that is formed in one of the legs of a substantially V-shaped member 27, more particularly near'the outer end of said leg. This member is shiftably disposed in a recess 28 in the upper face of the pinion 23, and is pivoted at 29 to the said pinion, the pivot 29'extending through the other leg of the member 27 at or near its outer end, and as near to the periphery of the inon as the structure Will permit. Rotation is imparted to the pinion 23 by means of an arm 30, that is provided with an upwardly extending sleeve 31, the latter being drawn over the standard 10, and provided with a milled knob 32. The arm 30 extends a little distance beyond the center of the pinion 23, and has in alinement with the center of said pinion a sleeve 33, that is rotatably arranged in the arm 30. This sleeve is provided with a screw threaded hole 34, the

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threads of this" hole meshing with those of a clamping screw 35, that is adapted to bear nai S101. 36, and in this Slot is Siidabiy disposed a split socket 37, intowhich may be inserted a scriber 38, for instance a pencil, a pen, or any other suitable instrument, as an engraving' point, etc. This socket and the scriber carried thereby may be adjusted in relation to the downwardlyy projecting ex-.

tension 21, for instance, by means of ascrew threaded spindle39, that is rotatably journaled in the bar, its threads engaging with ythose of a screw threaded hole 40 in the socket 37. To this spindle is fastened a milled knob 41', that is disposed beyond the outer end of the bar 20.

'1 he `operation of this device is as follows: It 1s to be observed that, if the centering point 11 of the standard 10 is driven inthe paper or other surface on which the ellipse is to bedrawn or described, and the arm 30 rotated around thelongitudinal axis of the said standard, for'instance by turning the knob32, the spur gear 14 will be kept stationary and the pinion` 23 will be caused toY l travel around the circumference of said spurA gear and also to revolve on11ts own axis.

In other words,kthe spur gear v14 forms a sunwheel, and the pinion 23 a planet wheel. It 1s obvious that thelug 24, or in yother words the pivot connecting the bar 20 and the pinion 23, describes, in traveling around the aXls of the sun wheel, an epicycloid.

Inasmuch as the ratio between the lsun wheel and theplanet wheel is 2'; 1, it is obvlous that two epicycloids will be described by the lug 24 while the planet wheel makes one complete turn around the circumference of the sun wheel, said planet wheel rotating ting of the lug 24 in relation to the center during such travel twice around its own axls. i

It is to be observed that with a given setof the planet wheel 23, the difference between the major and minor axes of the ellipse spredetermined, the difference being obviously four times the distance of the lug 24 from the center of thel planet wheel, or' in other words four times the eccentricity of the lug 24. The difference between the two axes ofthe ellipse to be described can be varied thus by loosening the vclampingscrew 35, and shifting the V- shaped member 27 around its pivot 29 until .the desired eccentricity of the lug 24 has been obtained. After this, the clamping ments ixedly in these positions. to describe an ellipse, first of all the split socket 37 with thescriber therein is shifted upon the bar 2O tothe desired position. The lug 24 is then brought to the proper position and the clamping screw set to hold it therein. The centering point of the standard l0 is then driven into the surface on which the ellipse is to be drawn, and held against rotation by holding one of the fin'- gers of one hand upon the knob 12. The knob 32 of the arm 30 is then taken hold of by two fingers of the same hand, and the said armrotated around the center of the gear '14. Let us suppose that, in starting the drawing of an ellipse, the lug 24 is in the' position marked in Fig. 5 of the drawings by the numeral I, that is to say it is in the position nearest in relation to the sun wheel 14. When in this position, the

-screw 35 is screwed down to hold the ele- In order marker 38is located in the major'axis 42 I of the ellipse. As now the planet wheel turns around the circumference of the sunI Wheel and revolves around its own axis in the direction of the .arrow designated in Fig. 5 of the drawings by the characterA, it will be observed that by the time this planet wheel has made yone-half of Va. revolution around its own axis, or in other words a quarter of a turn aroundv the circumference of the sunA wheel, the lug 24 arrives at the position denoted by the numeral II, in which it is at its farthermost point in relation to the circumference of the sun wheel, and in-this `position the marker 38 is located in the minor axis of the ellipse. In so traveling vthe marker describes one-quarter of an ellipse, as clearly shown lin Fig. 5 of the drawings, the remaining three-quarters being drawn in the same manner.

Attention is called to the fact that, if the eccentricity of the lug 24 is zero, that is'if the axis of the said lug coincides with that of the clamping screw l35, the difference between the major and minor axes will also .bef zero, or in other words a circle will be .described by rotating the arm 30 and the `parts connected therewith around the axis vof the standard 10.

From ,the foregoing it appears that with l eccentricity of the lug 24 must be adjusted.

`What I claim is.:-

1. Iny an ellipsograph, the combination with a standardhaving a centering point, of a spur gear rigidly secured thereto, a

horizontally extending slotted bar shitably and rotatably mounted on said standard, a marker carried by said bar, a pinion eccentrically pivoted to said bar and meshing with said gear, and an arm rotatably mounted upon said standard and pivotally connected with the center of said pinion.

2. In an ellipsograph, the combination with a standard having a centering point,

10 of a spur gear rigidly secured thereto, a

"l horizontally extending slotted bar shitably and rotatably mounted on said standard, a

marker carried by said. bar, a pinion eccentrically pivoted to said bar and meshing with said gear, an arm rotatably mounted upon said standard and pivotally connected with 4the center of said pinion, and means GEYZA TTH. 

